Device for sharpening



(No Model.)

' F. A. GRACE.

- DEVICE FOR SHARPBNING ROCK DRILLS.- No. 397.230.

Patented.]? 5

v 'INVENTOR M-ZOZnQZ 6'2 ace, MW m Lr/www.

v pacity of the drill. I

the formation of steel by forcing it while hotlina,

"cavity and causing cavity.

PATENT Fries.

REDERI K A. GRACE, or HICKORY, NORTH CAROLINA.

DEVICE FQR SHARPENING ROCK DR-lLLS SPECIFICATION forming part of Letters Application filed June 2, 1888.

To all whom it may concern;

Be it known that I, FREDERICK A. GRACE, a citizen of the United States, residing in Hick-. ory, Catawba county, and State of North Garohaveinvent-ed a new and useful Improvement in Swages for. Forming Rock-Drills, of which the following is a specification, reference being had to the accompanying drawings.

' My invention relates to improvements in swages for fornnng or sharpening a rockdrill so as to give it a superior arrangement of cutting-edges that will increase the cutting ca- The swage is adapted for by a heavy blow or pressure into the 'swageitto take the torn'i'ofthe My invention consists of a new anduseful improvement, which I shall fully describe in my following specification, and which I shall clearly set forth inmy claim, 1

In the accompanying drawings, F a front view ofthe swage, showing its general outline and the cavity in its face, a'b indicate of the swage.

division between the two parts Fig. 2 indicates a rear perspective view of the two halves of the swage along lines at of Fig. 1, each being formed so that ing the-line of Q the parts of one fit closely into'the correspondwith the plane of .spective view joined together as v v I of the swage in which the drill is shaped. sectional view .of both shape the ing parts of the other. Fig. 3 is'a front perof the two halves of the swage, opposite view fromthat shown in Fig. 2, and showing the two halves, which, in Fig. 1, form the cavity giving an Fig. 4 is a vertical halves of the swage separated. Fig. 5 is a view of the two parts combined and joined together by the movable. and adjustable band 0, as is necessary to resist the expansion of the metal of the drill when it has been placed in position and. the blow has been struck to lines of the drill.

In Fig. i is the plane-surface of the division of the two parts of the swage which corresponds with the'plane g h i j of the half B, Fig. 4. The plane a b 'c' 61', formed at an oblique angle division 0 de f, is parallel g h, the latter forming the t0 the plane e f the plane of division as the Patent No. 397,230, dated February 5, 1889.

Serial No. 275,828. mamas.)

' former plane, but opening in an opposite direction. The plane d c f the edges d c and f e of the plane a b e d and parallel plane 6 f g h. In the half B 'gle withv the plane a:" g" j" y, and the plane 4r" j" 1 forms a like angle with the plane g' h i'j', so that when the two halves of the swage are connected together the angles of the half A closely fit into the opposite angles of the ha-lfB.

In Fig. 4 in the half A, 1 2 g b is an oblong -rectangular cavity sunk below the surface of the plane or? e f, the plane 5 6 7 c 9 lying parallel to the plane 0 d e f. The opening in the cavity isformed'b'y the lines 1 5 6 2. c 1/ indicate a line at which the plane a b c d extends to the cavity 1 2 .g b; At this line a beveled plane, I) c 9, forms an oblique angle with the plane (1. b' c d, the plane 11' c 9 forming also of the'cavity 5 6 7 c 9 and with the plane side of the cavity 1 5 9 b at cf' g, and theplane c f g 7 intersects at'an oblique angle the plane 0' "'c'f and the plane ef' g h. The plane a f g 7 forms also an oblique angle with the plane 5 6 7 c 9 and also with the plane side of the cavity 2 G 7 g, so thatI have the bottom of the cavityin'the half A'bounded by a triangular side, I) c 9, and the irregular figure c f g 7. These figures form one half B there are corresponding figures, the lower side of the triangular facet of the drill in the side B being formed by the line lower angular edge of the irregular facet of the side B being formed by the angle b c f, so that when the sidesA and'B are joined together the cavity in A and the cavity in B form one rectangular cavity for the reception of the drill metal. The triangle 1') c 9 of the the side B, and the 2 in the half A of the swage, c d e f" of the sideA is opposlte tothe triangular facet of the side B. y

m and 'y indicate two projecting pins on 7 either side of the half A, made to fit into corresponding indentations, :13 y, in the side B, so that when the twosides are placed together the projections, tend to hold the two halves firmly together e is bounded by an oblique angle with the planeofthe cutting-edges of the drill. In .the halffignre A is opposite to the irregular facet of the plane w" m" y" 2" forms a depressed anf g, and the 10c fitting into the indentations,

and to hold the angles of the cavity rigidly in position. The formation of the two halves of the swage is,- Fig. 5, shown to be more or less Wedgeshaped. This is done in order that the band 0 may lit overthe outside surface of the wage when put together, and may be driven down so as to produce a constantly-increasii'ig binding force upon the two parts A and B of the swag'e.

It will be seen that if the two parts of the swage are bound together as indicated in Fig.

5, by the band 0 and a piece of steel heated to the requisite temperature is driven into the cavity indicated in Fig. 1 the. steel will. receive the form of the sides of. the cavity, so that a drill will he produced having; its outting-edges formed by the beveled sides Z? c 9 and cf g 7 of the one half of the sivage and corresponding beveled sides on the opposite half of the swage. It is upon this peculiar form of the cavity of the swage thatl base my invention. cutting-power to the drill Whatever may he the means by which the drill is operated.

What I claim as new, and desire to secure by Letters Patent of the United States, is-

This formation secures greater semen A swage divided in two parts, having in one I half, A, the plane a b c (1, parallel to the i plane ef g h, and the two, forming equal angles with the plane (1 e f 1;, made to correspond to and fit into the opposite plane suri faces of the half 15, and having a rectangular i cavity in the side A, bounded on the lower P side by the triangular plane figure I) c 9, placed at an oblique angle with the planes which it intersects, and the irregular plane i c f g 7, also atohlique angles with the planes l which it intersects, the planes 6' c 9 and c i f g 7 eorrespondingwith planes of similar shape and formed upon the side B, so that the base of the triangular taeetin B shall'be f g i and the base-lines of the irregular facet in B l shall correspond to I) f in A. E In testimony of all which I have hereunto subscribed my name.

FREDERICK A. GRACE.

Witnesses R. J. .Iinnnoon, H. T. HARRIS. 

